Skids and pallets are rigid platforms which are used for the assembly, storage, stacking, handling and transportation of goods as a unit load, and traditionally have been and are still made of wood.
The construction of a pallet and a skid are generally similar. A pallet comprises a top deck, a bottom deck and a plurality of stringers to support both the top and bottom deck boards. In contrast, a skid comprises of only a plurality of top deck boards, and a plurality of runners which support the top deck. In short, the primary difference between the two is that a skid does not have a bottom deck. A skid may also be considered as a pallet without a bottom deck.
Due to the similar function and appearance of skids and pallets, it is common for laymen and even the logistic industry to inaccurately refer to a skid as a pallet and vice versa.
Skids and pallets are traditionally manufactured from raw wood which originate from living or dead trees. However, the raw wood used is often infested by pests such insects and beetles, and may not have been sufficiently processed or treated to remove or exterminate the pests. The possibility of such pests being spread by infested wooden skids and pallets, and the threat posed by invasive pests to the ecology and agriculture of a country is a cause for serious concern.
In accordance with the ISPM-15 Standard which regulates the use of wood packaging material in international trade, raw wood used for skid and pallet production have to be heat treated or chemically fumigated to exterminate and prevent the spread of pests through the shipment of goods by importation or exportation.
Wooden skids and pallets are also often discarded after use, or when damaged. The relatively short life span of wooden skids and pallets coupled with the competing demand for raw wood by other industries (such as the furniture industry) makes wooden skids and pallets not only wasteful but also expensive.
In view of these drawbacks, wooden skids and pallets have accordingly been supplemented by skids and pallets which are made of plastic and paper materials, which are exempted from the ISPM-15 Standard.
However, plastic and paper skids and pallets are not without drawbacks, and each has their associated problems.
Plastic skids and pallets are generally durable, and are not subject to the ISPM-15 Standard. While this is an important and obvious advantage, the unit cost of a plastic skids or pallet is prohibitively high due to the cost involved in tooling and mould making.
The industry has also seen the introduction of skids and pallets which are made of paper materials. Paper materials in this context, relates to thick laminated paper sheet, card stock and also corrugated paper. Skids and pallets made of paper materials have proven to be a viable and more cost-effective alternative. The wide acceptance of skids and pallets made of paper materials has generated a whole industry dedicated to the design and production of such skids and pallets.
There has accordingly been a veritable selection of paper skids and pallets, some of which are constructed from intricate and complex designs stamped on singular laminated paper or card stock with numerous fold lines, tabs and slots which must be bent and folded in many sections to form a finished skids or pallet, and some which are constructed from separate components which are made of laminated paper or card stock of different shapes and thicknesses, which have been subjected to rolling or folding to form structural components, which are then combined to form a complete skids or pallet.
The document U.S. Pat. No. 8,291,836 B2 (Jian, et al.) discloses a paper pallet which has a load bearing structure comprising of a plurality of first and second support members designed to engage and interlock with one another. Each support member is formed from paper or card stock cut to a specific and intricate shape and incorporating a plurality of interlocking slots, which is then bent and folded together. The first support member interlocks with a second support member via an interlocking slot.
Although such a paper pallet is a viable solution to the problem of wooden pallets, it along with other similarly complex paper pallets involve significant geometric design with a high degree of precision, the fabrication of tooling for producing two different support members with its associated fold lines and slots, and also substantial labour to bend, fold and assemble the cut paper stock. All of these add to the cost of production.
The document WO 2009/034495 A1 (Chong) discloses a paper pallet constructed from a combination of T-shaped elongate elements, channel members (i.e., an elongate U-shaped or C-shaped element) and hollow core inserts. As can be seen in the document, such a pallet combines two L-shaped elongate elements to form a T-shaped elongate element, which is inserts into a slot cut into a channel member, and each channel member includes a plurality of hollow core inserts.
The L-shaped elongate elements are generally constructed from paper angle board material which is made of laminated paper, which are produced by an angle board making machine.
The use of paper channel members in the construction of a paper pallet does in fact help create a robust load-bearing structure. However, the production of a channel member requires additional specialized machinery in the form of a paper channel making machine. The requirement for additional machinery in turn results in additional cost and capital expenditure, or possibly requires the inclusion of an additional vendor in the supply chain at the very least.
Furthermore, the cutting of slots on each channel member is also a task which requires precision and also additional tooling and an additional process in its manufacture.
It can be seen that a paper pallet which makes use of paper materials of multiple shapes, although practicable, is far from ideal from an economic point of view.
Finally, the document WO 2011/108915 A1 by the applicant discloses a paper pallet that comprises a plurality of elongate members forming a top portion of the pallet and a plurality of beams secured to the plurality of elongate members in a criss-cross manner to form a bottom portion of the pallet, with the plurality of elongate members and beams being constructed from a plurality of supporting elements and a plurality of L-section elements. The supporting elements typically being comprised of lengths of cylindrical shaped sections or half-cylindrical sections, which are made from paper core due to its strength and rigidity.
The paper pallet according to WO 2011/108915 A1 is also a viable alternative to wooden pallets. However, its reliance on paper core has a number of disadvantages. Paper core as its name suggests, is made of laminated paper which has been formed into a hollow cylindrical core, and is used in the supply of industrial paper. New paper core material is readily obtainable from paper manufacturers. However, new paper core material is considered relatively expensive, which adds significantly to the cost of manufacturing the paper pallet.
It is more economical to re-use paper core which has been discarded by the printing industry as a by-product. However, the printing industry is not necessarily a consistent or reliable source of paper core, and its availability is obviously dependent on the industry's rate of usage of paper. Discarded paper core may occasionally be short in supply or difficult to obtain during lean periods in the printing industry.
A further disadvantage of the paper pallet according to WO 2011/108915 A1 is in its disposal. The plurality of elongate members used in the top portion of the pallet and the plurality of beams are made of L-section longitudinal elements, and when the pallet is dismantled for disposal, the L-section elements may be fed through an industrial shredder. However, the supporting elements made of paper core are often too thick and rigid to be shredded by the same equipment.
In view of all the disadvantages described above, it is desirable to have a skid or pallet made of paper materials that is simpler in design and construction, and that is more economical to manufacture.
The present invention was developed in consideration of the above requirements.